The present invention relates generally to cotton candy machines and methods of making cotton candy, and more particularly, to an improvement in cotton candy spinner heads.
Machines for spinning granular sugar into sugar filaments or xe2x80x9ccotton candyxe2x80x9d are generally known and have been employed for some time at events such as carnivals, fairs and circuses. A typical cotton candy machine is operable to heat sugar granules into molten sugar and to then cast or spin the molten sugar into a fiber or strand form using centrifugal force. The candy fibers or strands cool or congeal and are then directed into a bowl or tub where they are usually gathered on a stick or rolled paper tube for service and consumption. The sugar is usually colored to impart a color to the finished candy.
In order to carry out the heating and spinning function, a typical cotton candy machine includes a base which houses a motor for driving a rotatable shaft. A spinner head is mounted to the shaft to be rotated and defines a chamber for receiving raw granular sugar. The spinner head includes one or more heating elements positioned therearound, which melt the raw sugar granules into a molten form. The rotation of the spinner head actually causes the sugar to contact the heating elements for melting. Annular slots or perforations are also formed in the spinner head and surround the chamber and the heating elements. The rotation of the spinner head further imparts a centrifugal force on the molten raw sugar so that it is spun or slung out of the slots in the spinner head after it is melted and passes by or through the heating elements, forming sugar filaments. The molten sugar filaments cool or congeal as they are slung out of the spinner head and collect on the inner surface of a bowl or basket mounted on the base to surround the spinner head. The congealed sugar filaments in the basket are then transferred to a paper tube or the like by rolling an end of the tube about the circumference of the basket to collect the cotton candy on the tube end. Examples of cotton candy machines are described in more detail in U.S. Pat. Nos. 1,489,342; 3,036,532; 4,145,687; 4,872,821; 5,145,687; 5,441,754; 5,498,144; 5,766,643 and 4,872,821, which are all expressly incorporated herein by reference in their entirities for further detail of possible embodiments incorporating the aspects of the invention and for background detail.
Existing cotton candy machines use a variety of different heating elements. In some machines, the heating element is in the form of a flattened coil with vertically oriented coil turns formed of nickel nikrome. The coils are spaced closely together. The flattened coil is formed into the shape of a circular band and is held in a perforated heater holder. The heater holder is coated with aluminum oxide for electrically insulating the heater holder from the heating element. The sugar melts due to the heat of the heating element, and passes through the closely spaced vertical coils of the heating element and out of the perforations of the heater holder. Such a design provides uniform heat over a significant portion of the heater holder.
In other machines, the heating element is also a coil, except with only three or four horizontally oriented turns having large spaces therebetween. A mesh screen is used in conjunction with such a coil to keep the granular sugar from passing through the coil so that it can be melted. The heating element and screen are then placed inside a perforated ring. Such a heating element tends to only provide heat right at the three or four turns and thus does not uniformly melt the sugar. As a result, the cotton candy is sporadically formed from the spinner head. While such cotton candy machines have been utilized successfully in the past, they have still several drawbacks, in addition to those previously mentioned.
In particular, the heating elements of various of the cotton candy machines referenced above have certain drawbacks. Many such heating elements require various parts which must be properly formed and fabricated to operate within the particular design of the spinner head. For example, the heating elements must be specifically formed and configured to efficiently melt the sugar within the spinner head but to also allow the molten sugar to pass through and out the spinner head. The heating elements also must be mounted and seated properly in the heater holder of the spinner head.
Furthermore, the coil of the heating element of some designs is uninsulated, thereby requiring a sophisticated, space-age and expensive dielectric coating to be formed on the heater holder. In addition to the expense, such coatings may chip, which makes the heating element prone to failure if it shorts to ground through the heater holder. Such fabrication complexities increase the cost of the machine and its manufacture and also make it more prone to malfunction.
In addition, the prior art heating elements create a ballast in the outside circumference of the spinning head. The centrifugal force on such a ballast causes undesired wear on the motor and bearings which turn the spinner head. Accordingly, it would be desirable to eliminate the ballast effect created by existing heating elements.
Still further, if tubular heating elements are used, they do not always uniformly and thoroughly provide heat over the surface of the spinner head which incorporates the perforations or slots through which the molten sugar passes. Accordingly, the heat applied to the molten sugar in the spinner head may be uneven and sporadic in certain areas of the spinner head. As such, it is desirable to provide more uniform heat throughout the spinner head so that sugar in the head is melted efficiently and uniformly around the spinner head.
In addition, other portions of the machine must be specifically fabricated to interface with existing heating element designs. For example, several of the cotton candy machines disclosed in the U.S. patents listed above, notably U.S. Pat. Nos. 4,872,821; 5,441,754; and 5,766,643, utilize a special spinner head ring or band with slots therein for slinging the molten sugar under centrifugal force. The band must also, however, act as a support or heater holder for the heating elements. As such, the band has to be specifically fabricated and formed to engage and partially encase the heating elements. As will be readily appreciated, machining the specialized parts further increases the overall cost of fabricating the cotton candy machine.
An additional drawback is created by the operation of existing heating elements. Such heating elements have been known to malfunction due to failure of the dielectric which they contact.
In view of the above disadvantages of prior art cotton candy machines, it is desirable to improve cotton candy machines and methods of manufacturing cotton candy and to reduce the complexity of the machine and process and thereby reduce its cost. Moreover, it is desirable to provide a cotton candy machine with fewer and simpler parts to further reduce costs and improve the operation, reliability, and heat characteristics of the machine.
To these ends, one embodiment of the invention provides an apparatus for making cotton candy which comprises a bowl and a spinner head mounted in the bowl and coupled to a motor for rotation of the spinner head about an axis. The spinner head comprises a perforated band which extends generally circumferentially around the spinner head to rotate with the spinner head. The perforated band includes a plurality of perforations, such as slots, which are formed therein for delivering molten sugar from the spinner head and into the bowl. In that way, cotton candy is made.
In accordance with one aspect of the present invention, a film heater, which includes a film operable for generating heat when electrical current is delivered thereto, is applied or thermally coupled against a surface of the perforated band. The film heater applied against the band surface is operable for supplying heat to the system and melting sugar proximate the perforated band to make cotton candy. The film of the film heater is relatively thin and eliminates the bulk and ballast associated with prior art heating elements.
In one embodiment of the invention, the film heater may comprise a resistive film which is applied directly onto a surface in a desired manner and pattern for forming the film heater. The resistive film might be applied directly to a surface of the band, such as by being deposited, plated, or printed onto the band surface. Generally, when the film is applied directly to the surface, an electrically insulative layer of material separates the film and the band for electrical isolation of those elements.
Alternatively, the film may be applied to a separate substrate to form the film heater which intermediate substrate is then positioned or applied against the surface of the perforated band. The film might also be incorporated into or onto a flexible substrate to form the film heater, which flexible substrate is then coupled or otherwise applied to the band surface. Various appropriate film materials may be utilized to form the film heater. In one aspect of the invention, a resistive film (e.g. resistive ink) may be used.
In accordance with another aspect of the present invention, as noted above, electrically insulative materials might be utilized around the film, such as between the film and the band surface, or on an outside surface of the film. For example, various dielectric materials are suitable for such purposes. The dielectric materials prevent the film from shorting to the perforated band or to other conductive surfaces, and prevent shock hazards.
In accordance with another aspect of the present invention, the film of the film heater is generally coextensive with a significant portion of the band surface for uniformly and thoroughly heating the sugar which contacts the heater and band surface. To that end, the film might be formed somewhat coextensively with the band surface, leaving appropriate openings for the sugar to pass through. Alternatively, the film may be formed in a specific pattern which is contained within the boundaries of the band surface.
In accordance with another aspect of the present invention, the band has perforations or openings therein which are configured for preventing granular sugar from passing through the band unmelted, and for ensuring a fine, not coarse, cotton candy product. In an embodiment of the invention where the film is deposited directly on the band, the film, and the film heater formed thereby, have open areas which are generally coextensive with portions of the band apertures. As such, the invention eliminates various parts and structures from prior art machines which were configured to capture the granular sugar until it melted. In the present invention, the perforations of the band are configured to ensure melting of the granular sugar and to ensure that molten sugar is predominantly spun from the machine at the desired size for the strands.
One embodiment of the invention utilizes a spinner head having an upper head and a cap wherein the perforated band and film are positioned between the upper head and cap. The upper head and cap may be formed of a rigid material, such as a polymer, while the perforated band may be formed of a suitable material, such as stainless steel or aluminum.
The present invention provides significant advantages over the prior art by simplifying the design, and therefore, the fabrication of the cotton candy machine and thereby reducing its cost and increasing its reliability. Furthermore, the present invention provides a uniform application of heat over the surface of the perforated band which is contacted by the sugar to efficiently melt the sugar. Furthermore, the design of the perforated band is simplified and the ballast of prior art heating elements is significantly reduced. Therefore, the reliability of the cotton candy machine is further enhanced. Still further, the operation of the film as a film heater within the cotton candy machine of the invention reduces the possibility of heater malfunction.
These advantages, and other advantages of the present invention are set forth in greater detail hereinbelow.